title: Reduced acetylcholinesterase activity in the fusiform gyrus in adults with autism spectrum disorders.
abstract: BACKGROUND
  Both neuropsychological and functional magnetic resonance imaging studies have shown deficiencies in face perception in subjects with autism spectrum disorders (ASD). The fusiform gyrus has been regarded as the key structure in face perception. The cholinergic system is known to regulate the function of the visual pathway, including the fusiform gyrus.
  
  
  OBJECTIVE
  To determine whether central acetylcholinesterase activity, a marker for the cholinergic system, is altered in ASD and whether the alteration in acetylcholinesterase activity, if any, is correlated with their social functioning.
  
  
  METHODS
  Using positron emission tomography and a radiotracer, N-[(11)C]methyl-4-piperidyl acetate ([(11)C]MP4A), regional cerebrocortical acetylcholinesterase activities were estimated by reference tissue-based linear least-squares analysis and expressed in terms of the rate constant k(3). Current and childhood autism symptoms in the adult subjects with ASD were assessed by the Autism Diagnostic Observation Schedule and the Autism Diagnostic Interview-Revised, respectively. Voxel-based analyses as well as region of interest-based methods were used for between-subject analysis and within-subject correlation analysis with respect to clinical variables.
  
  
  METHODS
  Participants recruited from the community.
  
  
  METHODS
  Twenty adult subjects with ASD (14 male and 6 female; age range, 18-33 years; mean [SD] intelligence quotient, 91.6 [4.3]) and 20 age-, sex-, and intelligence quotient-matched healthy controls.
  
  
  RESULTS
  Both voxel- and region of interest-based analyses revealed significantly lower [(11)C]MP4A k(3) values in the bilateral fusiform gyri of subjects with ASD than in those of controls (P < .05, corrected). The fusiform k(3) values in subjects with ASD were negatively correlated with their social disabilities as assessed by Autism Diagnostic Observation Schedule as well as Autism Diagnostic Interview-Revised.
  
  
  CONCLUSIONS
  The results suggest that a deficit in cholinergic innervations of the fusiform gyrus, which can be observed in adults with ASD, may be related to not only current but also childhood impairment of social functioning.
authors.affiliation: Research Center for Child Mental Development, Hamamatsu University School of Medicine, Japan.
authors.forename: Katsuaki
authors.initials: K
authors.lastname: Suzuki
authors.forename: Genichi
authors.initials: G
authors.lastname: Sugihara
authors.forename: Yasuomi
authors.initials: Y
authors.lastname: Ouchi
authors.forename: Kazuhiko
authors.initials: K
authors.lastname: Nakamura
authors.forename: Masatsugu
authors.initials: M
authors.lastname: Tsujii
authors.forename: Masami
authors.initials: M
authors.lastname: Futatsubashi
authors.forename: Yasuhide
authors.initials: Y
authors.lastname: Iwata
authors.forename: Kenji J
authors.initials: KJ
authors.lastname: Tsuchiya
authors.forename: Kaori
authors.initials: K
authors.lastname: Matsumoto
authors.forename: Kiyokazu
authors.initials: K
authors.lastname: Takebayashi
authors.forename: Tomoyasu
authors.initials: T
authors.lastname: Wakuda
authors.forename: Yujiro
authors.initials: Y
authors.lastname: Yoshihara
authors.forename: Shiro
authors.initials: S
authors.lastname: Suda
authors.forename: Mitsuru
authors.initials: M
authors.lastname: Kikuchi
authors.forename: Nori
authors.initials: N
authors.lastname: Takei
authors.forename: Toshirou
authors.initials: T
authors.lastname: Sugiyama
authors.forename: Toshiaki
authors.initials: T
authors.lastname: Irie
authors.forename: Norio
authors.initials: N
authors.lastname: Mori
mesh_terms: D000085:Acetates; D000110:Acetylcholinesterase / Q000378:metabolism*; D000293:Adolescent; D000328:Adult; D001931:Brain Mapping; D002250:Carbon Radioisotopes; D002648:Child; D002659:Child Development Disorders, Pervasive / Q000000981:diagnostic imaging*; D003142:Communication; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008297:Male; D010880:Piperidines; D049268:Positron-Emission Tomography; D012016:Reference Values; D012919:Social Behavior; D013239:Stereotyped Behavior / Q000502:physiology; D013702:Temporal Lobe / Q000000981:diagnostic imaging*; D055815:Young Adult
chemical_list: D000085:Acetates; D002250:Carbon Radioisotopes; C100518:N-methyl-4-piperidyl acetate; D010880:Piperidines; D000110:Acetylcholinesterase